Prompt was from V Tsuion: Seven hundred years before our modern times... they saw shapes rising from the sea, in the distance... These were the Old Ones whose coming was foretold.
This was certainly a very unusual prompt, but my first thought was Lovecraft. As Lovecraft was before Holmes and Watson's time, I couldn't directly reference his books, but hopefully I gave the same feeling, or at least as much as I could as someone who knows very little about Lovecraft!
I did not notice the evening growing dark around me, so absorbed was I in my book. The menacing, eerie aura was unlike my usual reading, but Murray had recommended it to me in his last letter, and so I had tried it. Once I had started reading, I could not put it down, becoming enthralled by the almost gothic tale of creatures who inflicted a horror beyond human understanding.
"You should tell Murray he will owe you a pair of glasses, Watson."
I startled wildly and looked around. Holmes was kneeling by the fireplace, stoking, when last I remember it had been mid-afternoon and Holmes had said not to expect him back for hours. "I thought you were out tonight."
"I was." Upon a closer look, his collar was still wet from the rain that had been pouring down all evening. As Holmes would tell me, it was a simple deduction to say he had not long been back.
The fire roaring again, Holmes moved away from it as I blinked at the sudden light. "What time is it?"
"Past nine o'clock."
Knowing Mrs Hudson would be up soon with supper, I reluctantly put the book away. I still desperately wanted to finish it, but now that I knew what an enthralling effect it had on me, I would save it for a day I could afford to get lost in it!